Forest management/Data uncertainties limitations: Difference between revisions

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{{ComponentDataUncertaintyAndLimitationsTemplate
{{ComponentDataUncertaintyAndLimitationsTemplate
|Description==== Data ===
|Reference=FAO, 2010; IEA, 2012; Brown, 2000; Carle and Holmgren, 2008; UNEP-INTERPOL, 2012; FAO, 2001a; FAO, 2008;
FAO’s Forest Resource Assessment (FAO 2010) is the main data source used in the development and calibration of the forest management module, from which we derived data on wood production and deforested areas. In addition, national data were collected to parameterise the types and efficiency levels of forest management in different parts of the world (Arets et al., 2011). Further, the establishment of new forest plantations was designed according to planting rates reported and projected by the FAO (Brown, 2000; Carle and Holmgren, 2008).
|Description=<h2>Data, uncertainties and limitations</h2>
===Data===
The main data source for the development and calibration of the forest management module is FAO Forest Resource Assessment ([[FAO, 2010]]), from which data on wood production and deforested areas are derived. In addition, statistics from the International Energy Agency ([[IEA, 2012]]]) are used to estimate the regional fuelwood production, based on household fuelwood and charcoal requirements in national energy statistics. Finally, national data were collected to parameterise the type and production parameters of forest management in world regions (see details in [[Arets et al., 2011]]) and establishment of new forest plantations was designed according to planting rates reported and projected by FAO ([[Brown, 2000]]; [[Carle and Holmgren, 2008]]).


=== Uncertainties ===
===Uncertainties===
Several assumptions had to be made to project future wood production in forestry management systems. These pinpoint the uncertainties in the forestry management model. Better monitoring and reporting of these data would allow better calibration of the present forestry module.  
Several assumptions had to be made to project future production in forest management systems. These pinpoint the uncertainties in the forestry management model. Better data, monitoring and reporting would improve calibration of the IMAGE forest management module.


The regularly published FAO Forest Resource Assessment reports on the amount of industrially produced wood and the extent of primary and secondary forests, but not on the area from which these amounts are harvested, or on the use of different types of forest management. Moreover, the amount of wood produced in deforestation processes is not reported, probably due to the illegal nature of many such operations.  
FAO Forest Resource Assessment reports are published regularly on quantities of industrially produced wood and the areas of primary and secondary forests. However, these reports do not include the area from which these wood quantities are harvested, and the forest management system of these areas. The amount of wood produced in deforestation processes is not reported, probably due to the illegal nature of many such operations.  


Another lack in available data on forest use concerns the extent of illegal logging which is not captured in the FAO statistics and for which any very wildly estimates are available made for this (Nellemann & Interpol, 2012). As part of this, the data on extent of informal fuel wood collection from forests in developing countries are lacking (FAO, 2001, 2008). Only part of the fuel wood demand is assumed to be met by industrial forest harvesting, and estimates of total fuel wood demand are highly uncertain. Another uncertainty is the starting point: the state of forest use by age cohort as it was in 1970. As forests take from several decades to even a century to regrow after cutting, the effect of uncertainties in forest-use extends far into the future. Establishing a correct forest-use situation for 1970, requires assumptions or information on the forest use over the preceding century. However, there is no data available on historical forest use before 1970.
Few data are available on the extent of illegal logging, they are not captured in the FAO statistics, but in satellite-based assessments, and only very rough estimates are available ([[UNEP-INTERPOL, 2012]]). In addition, few data are available on informal collection of fuelwood in forests in developing countries ([[FAO, 2001a]]; [[FAO, 2008]]). Estimates of total fuelwood demand are highly uncertain ([[IEA, 2012]]), and fuelwood demand is only partly met by the forestry operations in this IMAGE module.  


=== Limitations ===
Another uncertainty is the starting point, which is the state of forest use by age cohort in 1970. As forests take several decades to a century to regrow after felling, the effect of historic uncertainties in forest-use extends far into the future.
In IMAGE, it is generally assumed that forests begin to regrow as soon as wood has been harvested, unless agriculture expands into that exact location. The only real modelled driver of deforestation is the net expansion of agriculture per certain region. However, there are many drivers of deforestation that are not related to agricultural expansion. So far, no global assessment model has included these other drivers, and therefore deforestation rates are calibrated, as they are in IMAGE. Although, the assumptions on these other drivers are highly uncertain, they largely determine future deforestation and deforestation emissions in scenario simulations.
 
===Limitations===
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Timber demand in IMAGE 3.0 is the total demand of sawlogs, pulpwood (both based on [[FAO]] for the historic period), and fuelwood (based on [[IEA]] and calculated by the [[TIMER model]]). The demand is fulfilled by harvesting wood from any type of forest without specifying the original source of demand. This can be relevant as different types of wood are used for timber, pulp and fuel. For fuelwood we assume that a certain fraction originate from informal sources, like gathering. For specific assessments it would be useful to include this detail in the allocation of forestry.
 
The timber demand in a region is the sum of local/regional demands and timber claims by other regions. The trade assumptions are adopted from external models, limiting the application of the model for cases with regional timber scarcity.
 
The only driver of deforestation modelled in IMAGE 3.0 is the net expansion of
agriculture per region. Many drivers of deforestation are not related to agricultural
expansion, but there is no global assessment of these other drivers. Therefore, total
deforestation rates in IMAGE are calibrated to FAO deforestation rates. Drivers and extent of deforestation are very uncertain and subject to debate, yet determine future deforestation and deforestation emissions in scenario simulations.
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Revision as of 14:46, 10 July 2017

Link to framework components overview

Parts of Forest management/Data uncertainties limitations

  1. Introduction page
  2. Model description
  3. Policy issues
  4. Data, uncertainty and limitations
  5. Overview of references
Component is implemented in:
Components:
Related IMAGE components
Projects/Applications
Key publications
References
Forest management module in IMAGE 3.0
Flowchart Forest management. See also the Input/Output Table on the introduction page. The option of forest plantations in IMAGE and LPJmL is still under development, and expected to be available soon.
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